This invention involves a self-lubricating ocular prosthesis and more particularly a prosthetic eye that is a source of lubricant and bactericide coupled with the method of use and method of manufacture of the prosthetic device.
For the person who has lost an eye due to injury, disease, or genetic defect, the art of the Ocularist has long been available to supply an ocular prosthesis including a prosthetic eye that almost exactly matches the person's natural eye. The ocular prosthesis may be necessary following an enucleation, an evisceration or the absence of an eye due to a congenital birth defect. In the vast majority of cases, an orbital implant is surgically implanted onto which the prosthetic eye is inserted. The artificial eye is cast from polymerized polymethacrylate resins using techniques well known in the art. An impression is taken of the eye socket from which is prepared a positive mold on which the synthetic eye is cast. A variety of prosthesis and techniques are used to provide movement of the artificial eye in concert with the person's good eye. These include an enucleation implant or an anophthalmic insert. More recently, orbital implants that are sufficiently porous that the patient's blood vessels and tissues grow into the implant allowing a surgical procedure to give artificial eye movement. A post or peg interconnection is provided between artificial eyes and orbital implants so that the eye moves with the orbital implant which follows the good eye.
Hollow prosthetic eyes have been offered since the 1960's and are more recently described in the article THE MAKING OF A HOLLOW PROSTHETIC EYE by Eric A. Jarling, JOURNAL OF AMERICAN SOCIETY OF OCULARIST, circa 1986. This hollow prosthesis is only offered for those patients whose anophthalmic cavity is larger and deeper than normal, specifically those patients that were unable to be fitted with an orbital implant at the time of enucleation, or had experienced extrusion of an implant and were unable to have a second implant. For those patients, the ocular prosthesis would be quite large, and thus heavier. In this manufacturing procedure, two halves of the artificial eye are produced with a hollow interior and bonded together to form an integral prosthesis. The interior cavity of this prosthesis is sealed to avoid intrusion of fluids and bacteria.
Even with these advancements, it has been long well established that for many patients, the blinking and tearing mechanisms of the eye socket do not operate at all or are insufficient to allow the patient comfortable use. The problem of eye dryness is reviewed in an article, ARTIFICAL EYES AND TEAR MEASUREMENTS, by Lee Allen, at al a reprint in OPHTHALMOLOGY, February 1980, Vol. 87, No. 2 of a presentation at the Eighty-Fourth Annual Meeting of the American Academy of Ophthalmology in November of 1979, the article being incorporated herein by reference thereto. In addition, continuing problems of bacterial infections are suffered by some prosthetic users. These problems are not unlike those associated with wearers of contact lenses, except the problem is more severe. The increased prevalence of bacteria in the conjunctiva of anophthalmic sockets is reported in the article, THE ANOPHTHALMIC SOCKET AND THE PROSTHETIC EYE-A CLINICAL AND BACTERIOLOGIC STUDY, printed in the Anophthalmic Plastic and Reconstructive Surgery Vol. 5, No. 4, pp 277-280, 1989, also incorporated herein by reference. In this study, the patients were instructed to handle their prosthesis as infrequently as possible, but about twenty-five percent admitted to removing their prosthesis at least once each week. The study concluded that this "frequent manipulation" increased the incidence of bacterial flora.
A number of techniques have been directed to the problem of dry artificial eyes including the use of BioCoat OPT supplied by Bio-Metric Systems, Inc. of Eden Prairie, Minn. This coating is a chemically bonded hydrophilic polymer that is applied to the artificial eye. Periodic retreatment of the coating is required. A solid methyl cellulose lubricant, marketed under the trademark LACRISERT.RTM., by Merk, Sharp and Dohme of West Point, Penn., has been developed and approved for severe natural dry eye problems by the U.S. Food and Drug Administration. This product is a small solid cylindrical body of lubricant that is inserted under the lower eyelid and allowed to slowly dissipate during the day providing a thickened film and lubrication for the natural eye. This product was also tested for use with artificial eye wearers with limited success. Unfortunately, the liquification of the LACRISERT.RTM. insert requires more liquid than is produced in the anophthalmic socket of many of the patients suffering from dry, unlubricated artificial eyes.
In U.S. Pat. No. 3,364,501 to Wilfred F. Stafford, et al, an inflatable orbital implant is provided with a passageway through the artificial eye to provide fluid irrigation offered to control the secretions which arise at the junction of the body tissue with the implant and create problems of infection and extrusion of the implant over varying periods of time. The Stafford procedure allows the insertion of a small tube to force an irrigating liquid through the passageway to the rear of the artificial eye and through a second passageway through the orbital implant.
Therefore, despite the continuing problem of dry eyes and bacterial growth, none of the devices, treatments or substitutes provide an answer to the problem and none of the devices or methods of the prior art attain the objects described hereinbelow.